How is detection and quantification of the separated protein accomplished in electrophoresis?

Using a densitometer

Name some commonly encountered problems in electrophoresis

Holes in staining pattern - analyte present in too high a concentration

Very slow migration - voltage too low

Sample precipitates in support - pH too high or low; excessive heat production

Describe Isoelectric focusing

A type of zone electrophoresis in which protein separation is based on the isoelectric point (pI) of the proteins

What is capillary electrophoresis based on?

Electroosmotic flow (EOF)

How does Amperometry work?

Electrochemical technique that measures the amount of current produced throught the oxidation or reduction of the substance to be measured at an electrode held at a fixed potential

What system does chloride coulometer employ?

Coulometric system

What law is the basis of the Coulometric system of a chloride coulometer?

Faraday's law

Describe Faraday's law

States that in an electrochemical system, the number of equivalent weights of a reactant oxidized or reduced is directly proportional to the quantity of electricity used in the reaction

If the current is constant, what is true with Coulometry?

The number of equivalent weights of reactant oxidized or reduced depends only on the duration of the current

How is the endpoint of the titration indicated in Coulometry?

Indicated by the increase in conductivity of the solution

What is used to measure the increase in conductivity of Coulometry?

Amperometry

What is a technique used to determine the concentration of a substance in solution employing and electrochemical cell that consists of two half-cells, where the potential difference between an indicator electrode and a reference electrode is measured?

Potentiometry

What is composed of single metallic conductor surrounded by solution of electrolyte?

Half-cell

What is also called an electrode?

Half-cell

In potentiometry, what type of connection is between two metallic conductors and between two electrolyte solutions?

Salt bridge

What is the universally accepted standard half-cell and at what potential?

Standard Hydrogen Electrode

Assigned a potential E degree of 0.000 volt

What type of electrode is Calomel?

Reference electrode

What does the Calomel reference electrode consist of?

Mercury covered by a layer of mercurous chloride in contact with saturated solution of potassium chloride

Name some types of reference electrodes

Calomel electrode

Silver-silver chloride (Ag/AgCl) electrode

What is another type of electrode used in potentiometry and how is it selected?

Indicator electrode

Selected on the basis of chage in its potential with change in concentration of analyte to be measured

What does a pH/blood gas analyzer use to measure blood pH?

pH sensitive glass electrode for measuring blood pH

What does a pH/blood gas analyzer use to measure gases in blood?

PCO2 and PO2 electrodes for measuring gases in blood

What does a pH/blood gas analyzer use to measure pH?

pH electrode (functioning glass electrode) that is dependent on properties of pH-sensitive glass

Name the different parts of a pH/blood gas analyzer used in measurements

pH-sensitive glass electrode

PCO2 and PO2 electrode

What does the PCO2 electrode specifically measure?

Partial pressure of carbon dioxide (PCO2)

What is the PCO2 electrode immersed in?

Bicarbonate solution

What type of potentiometric is the ion-exchange electrode?

Ion-selective electrode

How is K+ analyzed with the ion-exchange electrode?

Antibiotic valinomycin, because of its ability to bind to K+, is used as a neutral carrier for K+ elective membrane

How is NH4+ analyzed with the ion-exchange electrode?

Antibiotics nonactin and monactin used in combination as neutral carrer for NH4+, selective membrane

How is Sodium analyzed with the ion-exchange electrode?

Utilizes glass membrane electrodes with selective capability

Constructed form glass that consists of silicon dioxide, sodium oxide, and aluminum oxide